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A Novel Synthetic Procedure for Stereoblock Poly(propylene) with a Living Polymerization System
Author(s) -
Nishii Kei,
Shiono Takeshi,
Ikeda Tomiki
Publication year - 2004
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.200400032
Subject(s) - tacticity , methylaluminoxane , polymer chemistry , polymerization , heptane , chlorobenzene , materials science , copolymer , monomer , chemistry , polymer , organic chemistry , composite material , catalysis , metallocene
Summary: Propylene polymerization was conducted at 0 °C in heptane or chlorobenzene (CB) by an ansa ‐fluorenylamidodimethyltitanium complex combined with dried, modified methylaluminoxane that had been treated by dilution with heptane and successively repeatedly vacuum dried to remove any free trialkylaluminiums. The post‐polymerizations testified that the living polymerization proceeded irrespective of the solvent used. The heptane system gave the syndiotactic poly(propylene)s (PPs), whereas the CB system gave almost atactic PPs. After the first polymerization in heptane had been completed, the same amounts of propylene and CB were added for the second polymerization. This procedure gave the syndiotactic‐atactic stereoblock PP with narrow molecular‐weight distributions.Structure of the ansa ‐fluorenylamidodimethyltitanium complex and its application to the synthesis of syndiotactic‐atactic stereoblock poly(propylene)s reported here.